Adjustable transducer

Abstract

An adjustable transducer apparatus includes a transducer fixedly mounted on a metal plate, a saucer-shaped housing with a pair of concentric inner ridges, a planar annular cover plate, the rim of which rests of the outer ridge, a transducer element fixedly mounted on a metal plate, the rim of the metal plate resting on the inner edge, an "O" ring disposed in the housing between the cover plate and the metal plate for cushioning the metal plate against the housing, and a plurality of screws for adjustably fastening the cover plate against the housing so that the cover plate is pivoted about the outer ridge to produce a compression on the "O" ring, and that said "O" ring in turn holds the metal plate in place in the housing. The maximum alertness of the transducer is obtained by adjusting the screws and thereby adjusting the chamber formed by the housing and the planar annular cover plate.

What is claimed is: 
     
       1. An adjustable transducer apparatus comprising: a saucer-shaped housing with two inner concentric ridges;   a planar cover plate, the outer rim of which rests on the outer ridge of the two concentric ridges;   a metal plate;   a transducer element fixedly mounted on the center of the metal plate, the rim of said metal plate resting on the inner ridge of the two concentric ridges;   an "O" ring disposed in the housing between the planar cover plate and the metal plate and opposite the inner ridge for holding the metal plate against the housing; and   a plurality of screws for adjustably fastening the planar cover plate against the housing at intermediate points between the outer and inner ridges so that the planar cover plate is pivoted about the outer ridge to produce compression on the "O" ring and said "O" ring transmitting pressure to the metal plate of the transducer, wherein the alertness of the transducer is obtained by adjusting the screws.   
     
     
       2. An adjustable transducer according to claim 1, wherein the periphery of the metal plate is concave to retain the "O" ring. 
     
     
       3. An adjustable transducer according to claim 2, wherein the planar cover plate has a quarter toroidal surface to retain the "O" ring in position. 
     
     
       4. An adjustable transducer according to claim 3, the concave surface and the quarter toroidal surface mate with the "O" ring such that the metal plate is held securely in the same place in the housing. 
     
     
       5. An adjustable transducer according to any one of the claims 1 to 4, wherein the saucer-shaped housing is provided with a plurality of apertures through the housing wall thereof to the exterior from the chamber defined by the housing and the metal plate. 
     
     
       6. An adjustable transducer according to claim 4, wherein said transducer is coupleable to a receiver, said receiver to be positioned to enclose the entire face of the transducer, wherein the housing walls are tapped so that the tips of the screws are allowed to go therethrough and the tip ends of said screws are slotted so that final alertness adjustment can be made from the tips of the screws.